Apparatus for refrigeration



E. RICE. JR

APPARATUS FOR REFR IGERATION m 29, was.

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Dec. 29, 1936.

E. RICE. JR

APPARATUS FOR REFRIGERATION Original Filed July 14, 1930 3 Sheets-Sheet 3 llllllll |l v||lllllllllllllllllllllllllllllI.

WWW (7M Patented Dec. 29, 1936 UNITED STATES PATENT OFFICF- v APPARATUS Eon REFRIGERATION Edward Rice, Jr., New York, N. ,Y., assignor to International arbonic, Inc., New York, N. Y.,

a corporation of Delaware Original application July 14,1930, Serial No.

1930 l 13 Claims.

This invention relates toimprovements in methods and meansfor refrigerating by use of solid refrigerants, such as Water ice (Solid H2O) and carbon dioxide'ice (solid C02).

A principal object of the invention is to provide a method of refrigerating by means of solid refrigerants that shall be more efficient than the prior methods and shall permit of close regulation of the effective refrigerating temperature.

Another object of the invention is to provide a method of refrigerating by means of solid'refrigerants 'whereby the effective refrigerating temperatures are to a substantial degree independent of the volume of the refrigerant, and

to thislatter end, the invention contemplates the provision of a method for materially increasing the refrigerating eflici'ency ofrelatively small quantities of a solid refrigerant.

-More specifically, an important object of the invention is the provision of a method of refrig eration by the use of a solid refrigerant which will produce effective refrigerating temperatures in the refrigerating chamber more closely approximating the melting or subliming temperature of the icethan the heretofore known methods, and which will maintain such temperatures .even' when the mass of ice has been reduced to relatively small dimensions.' 7

Still another object of the invention is the provision of a method of refrigerating by use of solid refrigerants which will permit a rapid acceleration in the rate of ice meltage or sublimation irrespective of the volume of the refrigerant when the temperatures in the refrigerated area are increased.

A still further object of the invention is to provide a methodof refrigeration by means of asolid refrigerant which will permit the refrigeration of practically any desired space whether occupied with a gas (including air), liquid, solid or acombination thereof without actual contact of the refrigerant with the contents of the space whereby when required the refrigerant may be entirely divorced from the refrigerated area.

A still further object of the invention is the provision of refrigerating apparatus for'use with a solid refrigerant in which the principal heat I transfer to therefrigerant takes place from the refrigerated space or mass to a conductor of high thermal conductivity and extended surface, and thence conductivcly to 'a relatively small surface ofthe refrigerant through a section of the conductor sufliciently large to transmit the required amount of heat for maintaining a predetermined cfiective refrigerating temperature.

Divided and this application July 3, 1936, Serial No. 88,878.

(or. oz-91.5)

In Canada August 5,

,The invention further contemplates the provision of refrigerating apparatus. for use interchangeably with solid C02, solid H20 or other solid refrigerant, in which the principal heat transfer to the solid refrigerant takes place fromthe refrigerated area or mass to a conductor of high thermal conductivity and extended surface,

thence oonductively to a relativelysmall surface of the refrigerant through a section of the con ductor of sufficient size to transmit an amount of heat required for maintaining a predetermined efiective refrigerating temperature and in which differences in the melting or subliming temperatures of the diiferent'refrigerants may be compensated by means of variable conductor resistances placed between the conductor and the refrigerant.

Still more specifically, as regards the use of solid H20 and similar solid refrigerants of relatively high melting point, an object of the invention is to provide a novel method of refrigeration which will produce effective refrigerating temperatures more closely approximating the melting temperature of the ice than has heretofore been possible, and will maintain such ternperatures even after the. volume of the ice has.

been reduced. to relatively small amounts.

Again specifically, and-as regards the use of solid refrigerants, such'as solid CO2, having a- ,relatively low melting point or point of sublimatio'n, another object of the invention-is to,pro-

vide a method of refrigerating with such refrigerants which shall be both hlghly 'efllcient and capable of close and accurate regulation of the effective refrigerating temperatures, said temperatures being maintainable even when the volume of the refrigerant has been reduced to relatively small amounts.

A still further object is the provision of refrigerating apparatus for use with solid CO2 or the like in which the effective refrigerating temperature is'controllable at least in part by means of insulation set up in an established principal A further and more specific object of the invention is the provision of a method of refrigeration by the use of carbon-dioxide ice or the like which-will permit the automatic maintenance of an approximately constant temperature in the refrigerating chamber under varying conditions of outside atmospheric temperature, of. content of refrigeratingchamber, and of ice supp y.

A further object of the invention is the provision of refrigerating apparatus for use with C: ice or the like in which the principal heat 7 transfer from the refrigerating chamber and its 7 contents to the ice takes place convectively from the chamber to a conductor of high thermal conductivity, thence conductively to the ice., and in which means may be provided for regulating the convection currents in such a manner that an approximately constant temperature may be maintained in the refrigerating chamber.

A further object of the invention is the provision of refrigerating apparatus for use with CO: "ice or the like in which the gas resulting from sublimation of the ice is retained in essentially gas-tight channels away from the contents of the refrigeratingchamber, and in which the gas escapes directly to the outside atmosphere or through piping of high thermal con ductivity placed in the top of therefrigerating chamber, thus permitting a secondary heattransfer from the refrigerating chamber and its contents to the escaping CO: gas.

A'further object of the invention is to provide a method of and apparatus for refrigerating by the use of C0: ice" or the like whereby an ini tialjrapid chilling of-the refrigerating chamber or its contents may be had when desirable by a comparatively rapid melting or sublimation of the ice,. and thereafter the requiredv temperature maintained by, a much slower sublimation of the ice" store. I A further object of the invention is the pro.-

duction of a refrigerating unit of suchcharacter' that it may beemployed either inhousehold and stationary refrigerators or in the refrigeration of railways cars, motor truck bodies, or other transportation units. 1

Still another object of the invention is to provide simple and relatively inexpensive refrigeratin'g units of a character adapted for use in household and other refrigerators employing solid H2O whereby my invention may be readily available faces to form' an open-ended duct *or ducts for for that class of refrigeration.

A still further object of, the invention istb provide a refrigeration unit in whicha wall is positioned adjacent the extended heat-absorbing surdirecting the convection currentsin the space to of Fig. 3, 75,

' flow of warmer air over said surfaces.

be refrigerated into contact with said extended surfaces, together with an open-ended auxiliary connecting duct or-ducts which lead to parts of the space to be refrigerated remote from the extended heat-absorbing surfaces and'which facilitate the Fig. 5 is a horizontal sectional viewers fur-' ther modification, the same being taken on line 5-5 of Fig. 6,

Fig. 6 is a vertical sectional view taken on line 6-6 of Fig. 5,

Fig. '7 is a semi-diagrammatic vertical sectional view through a refrigerator car equipped with refrigeration units constructed in accordance with my invention,

Fig; 8 is a horizontal sectional view through the car shown in Fig. '7, and

Fig. 9 is a detail sectional view illustrating the venting of the ice" cabinet or storage chamber.

Water ice or solid H2O is more widely used than any other form of refrigerant.- One of the principal drawbacks in the prior methods of using this refrigerant or,in fact, any solid refrigerant is that although any given mass of the refrigerant, no matter-how small, has a fixed refrigerating value; yet the smaller the mass becomes, the slower it's refrigerating action becomes also. This is due to the. fact that,the heat is usually either entirely or almost entirely brought to the ice convectively either by air or a liquid, and the amount of heat taken up by the refrigerant, other things being equal, depends directly on the'amount of the effective surface contact between the re-.

frigerant and the circulating fluid. Obviously as the ice melts, the surface area becomes less and the refrigerating action slower. In the construction of refrigerating apparatus, this feature, heretofore, has been given no consideration, and

no effort has been made to compensate for the rapid decrease in efficiency as the refrigerant 'Joses volume and surface area. As a,result, a

great deal of ice is'constantly being used with very indifferent or inferior results.

One reason that the mechanical household r'efrigerator-has progressed so rapidly is because the ordinary water ice refrigerator cannot maintain satisfactory refrigeration unless it is continually serviced and kept'practically full of ice at all.

times. For the same reason, a large and growing field for refrigeration of foodstuffs in motor transportation has avoided the use'of water ice and other 'solid refrigerants.

water ice as a refrigerant has been the used salt, a method of limited application which apparently cannot be greatly extended. e

I have discovered that the principal obstacles to the efilcientuse of water ice and other solid Practically the only. A method attempted to improve the emcie cy of refrigerants can be largely overcome if the heat from the space or material to be refrigerated is picked up by comparatively extended surfaces of a metal heat conductor, such as copper, aluminum or iron. and transferred through a substantial cross section of the metal. conductor directly to a surface of the body of ice with which the metal conductor. is either in immediate contact or in suitable conductive relation. I have found that by this method; the ice can be melted at practically a constant rate, thus providing a constant effective refrigerating temperature practically independent of the volume of the re-. frigerant, and even, with'extremely small masses of the latter. I have found also that the refrig erant can be melted at an almost inconceivable rate when large amounts of heat are passed over the extended metal surfaces. With a sufficient cross section of the conductor metal, assmall as thirty square inches of contact surface with the refrigerant is sufficient to melt enough. water ice to keep a good household refrigerator below F. even on the top shelf in the warmest weather; and after the doors have been opened as long as three minutes, this refrigerator will return to its original low temperature within twenty minutes or'one-half hour. It is essential in the practice of my invention that the solid refrigerant be maintained in conductive relation with a substantial metal conductor having a suitably extended surface area in the refrigerated space.

While the invention is of great importance in are desired and water ice is to be used by reason of its cheapness and availability, then a relative-- ly large amount of extended conductor or fin surface will be required because of the small temperature differential between the water ice and the temperature required; while the same temperature can be secured by use of solid carbon dioxide with considerably less surface area by reason of the fact that with solid carbon dioxide the conductor can be chilled to almost any temperature required down to say minus 50 F., and accordingly a relatively large temperature differential be maintained between the conductor and the refrigerated space. Obviously if temperatures are wanted near or below the melting point of water ice, then some other solid refrigerant maybe used with a sufliciently low melting or subliming point that the conductor can be put at a teme perature affording the differential required to maintain the refrigeration wanted. Frozen brine may be used especialy when put up in small and easily handled units in liquid-tight metal containers. The heat transferred from the conductor to the solid brine through the metal container, however, is not as constant and controllable as in the direct contact of water ice with the conductor or the contact of carbon dioxide ice with the conductorthrough a known amount of conducting resistance, as hereinafter more specifically set fort However, as the frozen brine can be provided with a melting point practically anywhere between 32 F. and considerably below zero and has now come intomore common useand also is comparatively cheap, it is apparent that it will have a limited use as a solid refrigerant means in my method of refrigeration. Of course, frozen brine directly in solid state can be used in the same way as water ice or carbon dioxide ice by permitting the melted .brineto drain off.

When using solid refrigerants such asbarbon. dioxide ice with a temperature considerably below the melting point of water ice, the use of predetermined known conductor resistances interposed between theconductor and the refrigerant is an important part of my method, as it affords a large degree of control over the action of. the refrigerant and a q ck convenient methodj-of varying the temperature of the extended conductor surface, and thus the effective refrigerating temperature. 7

It will be understood that for maximum control of refrigeration, with this type of refrigerant it is desirable to limit so far as feasible transfer of heat from the refrigerated space or mass to that passing through the conductor. This can be accomplished by providing adequate in-, sulation preventing transfer by radiation or by other than conduction through the selected constance, the valves are ductor. By thus establishing a principal and practically sole path of transfer and utilizing in conjunction therewith suitable known resistances, a substantially perfect control may be obtained. This method of control also affords a simple method for providing apparatus suitable for use with refrigerants such as water ice and carbon dioxide ice having widely different melting points. Thus a single refrigerating apparatus can be built that can use as a refrigerant either carbon dioxide or water ice or frozen brine, or, in fact, any solid refrigerant, and that can maintain practically any required tempera ture under constant outside temperature conditions within thelimits of the particular refrigerant used by a simple manipulation of conductor resistance interposed between the conductor and the refrigerant, and by providing in the same apparatus either manually orthermostatically-operated means to regulate the convection currents from the extended conductor surfaces or fins, the required temperature can be maintained irrespective of normal outside temperature varia tions.

In the form of the invention shown i Fig. 1, the numeral I40 designates a refrigerating. chamber having access doors I in the upper wall I42 thereof. The chamber walls are, of course, insulated in any usual or preferred manner and the upper wall I42 has formed therein an opening I43. Extending into the refrigerating chamber through this opening is an insulated cabinet I44 approximately gas-tight having an open top closed by an access door I45. The bottom wall Mia of this cabinet has imposed thereon a conductor plate I46 which may be conveniently constructed from copper, aluminum or some other metal having a suitably high factor of thermal conductivity. The edges of this plate project through the cabinet walls and are provided with vertically-extending vanes I41 projecting upwardly along the side walls of the cabinet and preferably constructed integrally with the plate 46. These vanes may have either a plane surface, or be transversely or longitudinally corrugated, the latter constructions providing an I increased surface for contact with convection currents.

Opposing the net toprovide channels I49 through which con vection currents may pass. The lower ends of these channels are closed by valves I 50 regulated through a thermostat I5I. In the present inand connected to the movable element I53 of the thermostat by a linkage generally designated preferably copper, and includes a coil I55a disposed in chamber "I40 for contact with the. convection currents of the chamber, preferably near the top of the chamber and where warm pocke areliable to occur. The outlet of the vent tube is placed below the inlet in order to induce aready flow of CO2 gas by syphoning, and is preferably equipped with a regulating valve Iii-which may be conveniently housed in a recess I58 formed in the wall of the cabinet.

The-interior of the cabinet'is preferably subdivided i'nto a plurality of sections by vertically 75 outer edges of the vanes are 5 insulated walls I48 which combine with the cabiillustrated as pivotally connected to the lower wall of the cabinet at I52 constructed of insulating material. These partitions are in the present instance illustrated as two in number so that three ice" spaces are formed. The bottoms of these ice spaces are formed by the plate I46 and upon the each "ice" space insulation I99 may be disposed between the "ice" and the plate, the thickness of this insulation varying in accordance with the conditions under which the refrigerator is to be employed. Insulation I69, the thickness of which may be varied, is removable and it willbe obvious that if two of the compartments have in the bottoms thereof insulation I", of a considerable thickness while the third compartment has no insulation as suggested in Fig. 1, or a relatively thin insulation as suggested in Fig. 6, the "ice of thislatter compartment will be sublimed more rapidly than that in the remaining compartments so that the ice" of this compartment acts as an initial chilling supply while that of I the.remaining compartments acts as a reserve P Thus e. first. mentioned ice" supply serves to rapidly reduce the temperature of the chamber when initially placed in operation or 3 when a rapid reduction of temperature therein is necessary following an opening of the access r doors MI.

If, for example, goods are placed in the refrigerator at their normal temperature and must be rapidly chilled, the insulation I99 maybe completely removed from one of the compartments so that the ice in this compartment will ing, or subliming the ice act very rapidly to reducethe temperature oft-the f chamber and to chid the goods to the.desired point. The desired temperature having been attained, the ice in the: remaining compartments is held in reserve to maintain this term perature thus materially increasing the period over which refrigeration is possible andparticularly adapting the apparatus for use in transportation of-perishable goods where facilities for replenishing the "ice store are poor. v

When pre-cooledproducts-are placed in the refrigerating chamber, then the bottoms of all of the compartments may be provided with insulation thus providing a maximum period of refrigeration for a given, "ice supply. By varying the extent to which they bottoms of the compartments are insulated from conductor plate I49 a limited control of the rate of melting of the "ice may be' obtained and thereby a limited control of the temperature of the storage chamber and.

contents secured.

A drip pan IOI is the cabinet for the from defrosting of spaces of the refrigerating ablyseparated from the i'or'aminous screens I92,

The principal amount of the heat used in meltis transferred by convection from the storage chamber and its contents to the ver ically extending vanes I41, thence conductively to the plate directly, or 'through insulation I99 to the "ice". A smaller amount of heat is transferred-by conpreferably disposed beneath reception of. water resulting vanes I41 and the storage chamber are prefercabinet spaces by duction' through the insulationt of the "ice" cabinet and 'walls' I49, and by internal. convection currents within the ice cabinet and the space surrounding the vanes I41. Control of the temperature of the storage chamber and conteiits is secured, in part by varying the size and character I", and

of the conduction plate I49 and vanes plate in the bottom of I49, thence conductivelyx of the insulations I44, I44a, and I48,

tents of the storage chamber during reduction to a desired level, as well as climatic and artificial changes in temperature outside the storage chamber may require a further means for securing a constant temperatureinside the chamber. This is achieved by the thermostatic or manual control of the convection currents through channels I49 and transferring more or less heat to conduction vanes I41 and plate I46. By these several means a variation of the rate of subliming or melting the carbon dioxide ice of as much as 1,000% can be attained which I believe is sufflcient to accomplish the objects of this invention.

The structure of Figs. 3 and 4 is substantially identical with that of Figs. 1 and 2, with the exception of the fact that the chamber I49 has its access door I 4Ia mounted in the side wall thereof and that communication between the channels I49 and the storage space in the upper ends of these channels instead of being made only through openings I63, formed in the insulating walls, includes one or more ducts I64 opening at the inner end through the wall of channel I49 and having the outer end disposed adjacent to the wall of the chamber I 49 or where .warm pockets are likely to occur. A further slight modification of the controlof the channel is employed in that the valves I5Ila instead of being supported by the cabinet, as in Figs. 1 and 2, are directly supported from and secured to the movable member I59 of the thermostat. The thermostat ception of the fact that conduction vanes are provided entirely about the cabinet walls and entrance to the convection channels is largely through ducts I64a, the intake ends of which are disposed adJacent chamber I49.

Units of the character shownare particularly adapted for use in conjunction with refrigerating cars, as diagrammatically illustrated in Figs. 7 and 8. As shown in these figures, a plurality of units will be'employed arranged about the side walls of the car and immediately beneath the top thereof. The ducts I64 are in each instance projected toward the center of the car, so that the intake'will be from the highest, and accordingly, the warmest part thereof.

This application is a division of my application for Method and apparatus for refrigeration, vSerial No. 467,999, filed June 14, 1930, now Patent surface for heat absorption from the space or material'to be cooled of greater area than the surface of the conductor presented in the refrigerant-containing chamber for heat transfer to the refrigerant, the capacity of said conductor to transmit heat along in the direction of the to the vertical walls of the refrigerant from the said surface presented for heat absorption being sufflcient, by reason of its thickness with respect to the heat conductivity of the metal from which it is formed and the area. of said extended surface exposed for heat absorption, tomaintain said heat-absorbing surface at an eif'ective'refrigerating temperature lower than that of the space or material to be cooled, whereby said heat-absorbing surfaceis adapted to absorb a larger amount of the heat to be transmitted by said conductor, togetherwithawall cooperating with said extended heat absorbing surface to form a generally vertically-extending duct through which air may flow from the space to be cooled into contact with said extended surface, and a horizontally-extending duct connected with an upper portion of said vertically-extending duct for facilitating the flow of warmer air over said extended surface from portions of the space to be cooled remote from said surface.

2. In refrigerating apparatus for cooling by a solid refrigerant such as water-ice, brine-ice. or solidcarbon dioxide, a solid metallic heating conductor having a vertically positioned extended surface for heat absorption from the space or material to be cooled of greater area than the surface of the conductor presented in the refrigerantcontaining chamber for heat transfer to the refrigerant, the capacity of said conductor to transmit heat along in the direction of the refrigerant from the said surface presented for heat absorptionpbeing sufficient, by reason of its thickmess with respect to the heat conductivity of the metal from which it is formed and the area of said extended surface exposed for heat absorption,

to maintain said heat-absorbing surface at an effective refrigerating temperature lower than that of the space or material to be cooled,whereby said heat-absorbing surface is adapted to absorb a larger amount of the heat to be transmitted by said conductor, together with a wall cooperating with said extended heat absorbing surface to form a duct through which air may flow from the space to be cooled into contact with said extended surface, and a duct extended in the upper part of the space to be cooled and communicating with the duct formed adjacent to said heatabsorbing conductor surface, said extended'duct facilitating the flow of warmer air over the heatabsorbing surface from portions of the space to be cooled remote from said surface.

3. Inrefrigerating apparatus for cooling bya solid refrigerant such as water-ice, brine-ice, or,

solid carbon dioxide, a solid metallic heating conductor having a vertically positioned extended surface in the form of fins forheat absorptionheat absorption, to maintain said heat absorbing surface at an efiective refrigerating temperature lower than that'of the space or material to be cooled, whereby said heat-absorbing surface is adapted to absorb a larger amount of the heat to be transmitted by said conductor, together with a wall cooperating with said extended heat absorbing surface to form a duct through which air may flow from the space to be cooled. into contact -with said extended surfaces, and a duct extended in the upper part of the space to be cooled and communicating with the duct formed adjacent to said heat-absorbing conductor surface, said extended duct facilitating-the flow of warmer air over the heat-absorbing surface from portions of the space to be cooled remote from said surface.

I 4. In refrigerating apparatus for cooling by a solid refrigerant such as water-ice, brine-ice, or solid carbon dioxide, a solid metallic heat conductor having a generally horizontally extending portion for supporting solid refrigerant in heat conductive relation therewith, said conductor also having a vertically positioned extended surface for heat absorption from the space or material to be cooled of greater area than the surface of the conductor presented in the refrigerant-containing chamber for heat transfer to the refrigerant, the capacity of said conductor to transmit heat along in the direction of the refrigerant from the said surface presented for heat absorption being sufficient, by reason of its thickness with respect to the heat conductivity of the metal from which it is formed and the area of said extended surface exposed for heat absorption, to maintain said heat-absorbing surface at an effective refrigerating temperature lower than that of the space'or material to be cooled, whereby said heat-absorbing surface is adapted to absorb a larger amount;

of heat to be transmitted by said conductor, together with a wall cooperating with said extended heat absorbing surface to form a duct through" which air may flow from the space to be cooled into contact with said extended surface, and a duct extended in the upper part of the space to be cooled and communicating with the duct formed adjacent to said heat-absorbing conductor surface,-said extended duct facilitating the flow of warmer air over the heat-absorbing surface from portions of the space to be cooled remote from said surface.

5. In refrigerating apparatus for cooling by a solid refrigerant such as water-ice, brine-ice, or solid carbon dioxide, a solid metallic heat conductor having a generally horizontally extending portion for supporting solid refrigerant in heat conductive relation therewith, said conduc-' tor also having a vertically positioned extended,

surface in the form of fins for heat absorption from the space or material to be cooled of a greater area than the surface of the conductor presented in the refrigerant-containing chamber for heat transfer to the refrigerant, the capacity of said conductor to transmit heat along in the direction of the refrigerant from the said surface presented for heat absorption being sufficient, by reason of its thickness with respect to the heatconductivity of the metal from which it is formed and the area of said extended surface exposed, for heat absorption, to maintain said heat-absorbing surface at an effective refrigerating temperature lower than that of the space or material to be cooled, whereby said heat-absorbing surface is adapted to absorb a larger amount of the heat to be transmitted by said conductor, to

gether with awall cooperating with said extended heat absorbing surface to form a duct through which air may flow from the space to be cooled intocontact with said. extended surface, and'a duct extended in the upper part of the space to be cooled and communicating with the duct formed adjacent to said heat-absorbing conductor surface, said extended duct facilitating the flow of warmer air over the heat-absorbing surface from portions of the space to be cooled'remote from said surface.

5. In refrigerating apparatus for cooling by a solid refrigerant such as water-ice, brine-ice, or solid carbon dioxide, a solid metallic heat conductor having a vertically positioned extended sur-' face for heat absorption from the space or-material to be cooled of greater area than the surface of the conductor presented in the refrigerant-. containing chamber for heat transfer to the refrigerant, the capacity of said conductor to transmit heat along in the direction-or the refrigerant from the said surface presented for heat absorption being suflicient, by reason of its thickness with respect to the heat conductivity of the metal from which it is formed and the area of said extended surface exposed for heat absorption, to maintain said heat-absorbing surface at an effective refrigerating temperature lower than that .of

the space or material to be cooled, whereby said heat-absorbing surface is adapted to absorb a larger amount of the heat to be transmitted by said conductor, together with a wall cooperating with said extended heat absorbing surface to form a generally vertically-extending duct through which air may flow from the space to be cooled into contact with said extended; surface, a horizontally-extending duct connected with an I upper portion of said vertically-extending duct for facilitating the flow of warmer air over said extended surface from portions of the space to be cooled remote from said surface, and-means for retarding the flow of air through the duct formed adjacent to said heat-absorbing conductor surface.

7. In refrigerating apparatus for cooling by a solid refrigerant such as water-ice, brine-ice, or

solid carbon dioxide, a solid'metallic heat conductor having a vertically positioned extended surface for heat absorption fromthe space or ma-' terial to be cooled of greater, area than the surface of the conductor presented in the refrigerant-containing chamber for heat transfer to the refrigerant, the capacity of said conductor to transmit heat along in the direction of the refrigerant from the said surface presented for heat absorption being sufllcient, by reason of its thiclif ness with respect to the heat conductivity of the metal from which it is formed and the area of said extended surface exposed for heat absorption,

to maintain said heat-absorbing surface at an effective refrigerating temperature lower than duct for facilitating the flow of warmer air oversaid extended surface from-portions of the space I that of the space or material'to be cooled, whereby said heat-absorbing surface is adapted to absorb a larger amount of the heat to be transmitted by said conductor, together with a wall cooperating with said extended heat absorbing surface to form a generally vertically-extending duct through which air may gflow from the space to be cooled into contact with said extended surface, a horizontally-extending duct connected with an-upper portion of said vertically-extending to be cooled remote-from said surface, and means for controlling the flow of air through the duct formed adjacent to said heat-absorbing conductor surface. a

8. In refrigerating. apparatus for cooling by a solid refrigerant such as water ioe, brine-ice, or solid carbon dioxide, a solid metallic heat conductor having a verticallypositioned extended surface for heat absorption from the space or material to be cooled of "greater area than the surface of the conductor presented in the refrigerant-containing chamber for heattransfer to -mation of the refrigerant.

to absorb a larger amount of the heat to be transmitted by said conductor, together with a wall cooperating with said extended heat absorbing surface to form a generally vertically-extending duct through which air may flow from the space to be cooled into contact with said extended surface, a horizontally-extending duct connected with an upper portion of said vertically-extending duct for facilitating the flow of warmer air .over said extended surface from portionsof the space to be cooled remote from said surface, and

thermostatic means for regulating the flow of air through the duct formed adjacent to said heatabsorbing conducting surface in accordance with the temperature in the space to be cooled.

9. In refrigerating apparatus for coolingby a solid refrigerant such as solid carbon dioxide,

, a closed chamber for the refrigerant, a portion of said'chamber including a solid metallic heat conductor in heat exchange relation to refrigrant therein and having an extended surface for heat absorption from the'space or material to be cooled of greater area thanthe surface of the conductor presented-in the refrigerant-contain ing chamber for heat transfer to the refrigerant, the capacity of said conductor to transmit heat along in the direction ofthe refrigerant from the said surface presented for heat absorption being sufllcient, by reason of its thickness with respect to the heat conductivity of the metal from which it is formed and the area of said extended surface exposed for heat absorption, to main- ,tain said heat absorbing surface at an effective refrigerating temperature lower thanthat of the space or material to be cooled, whereby said heat absorbing surface is adapted to absorb a larger amount of the heat to be transmitted by said conductor, a gas escape pipe leading from the frigerating apparatus, and meansoperable from without the chamber for permitting escape of some gas generated by the evaporation or subli- 10. In refrigerating apparatus for cooling by a solid refrigerant such as solid carbon dioxidaa closed chamber for the refrigerant,,a portion of said chamber including a solid metallic heat con ductor in heat exchange relation 'to refrigerant therein and having an extended surface for heat.

absorption from the space or material to be cooled of greater area than the surface of the conductor presented in the. refrigerant-containing chamher for heat transfer to the refrigerant, the capacity -of said conductor to transmit heat along ,in the .direction. or the refrigerant from the said surface presented forheat absorption being safe flcient, by reason of its with respect to the heat conductivity of the metal from whichit is formed and the area of said extended surface exposed for heat absorption, to maintain said heat absorbing surface at an eifective refrigerating temperature lower thanithat of. the space or '50 refrigerant chamber to the outside of there material to be'oooledwhereby saidheat absorbing surface is adapted to absorb a larger amount of the heat to be transmitted by said conductor, a gas escape pipe leading from the refrigerant chamber to the outside of the refrigerating apparatus, and a valve in said pipe and operable from without the chamber for regulating the escape of gas generated by the evaporation or sublimation of the refrigerant.

11. In refrigerating apparatus for cooling by a solid refrigerant such as solid carbon dioxide, a

closed chamber for the refrigerant, a portion of said chamber including a solid metallic heat conductor in heat exchange relation to refrigerant therein and having an extended surface for heat absorption from the space or material to be cooled of greater area than the surface of the conductor presented in the refrigerant-containing chamber for heat transfer to the refrigerant, the capacity of said conductor to transmit heat along in the direction of the refrigerant from the said surface presented for heat absorption being sufficient, by reason of its thickness with respect to the heat conductivity of the metal from which it is formed and the area of said extended surface exposed for heat absorption, to maintain said heat absorbing surface at an efiective refrigerating temperature lower than that of the space or material to be cooled, whereby said heat absorbing surface is adapted to absorb a larger amount of the heat to be transmitted by said conductor, a gas escape pipe leading from the refrigerant conductor to the outside of the refrigerating apparatus, said gas pipe extending through a portion of the space to be refrigeratedand in heat conductive relation therewith, and a valve in said pipe and operable from without the chamber for controlling the passage of gas therethrough.

12. In refrigerating apparatus for cooling by a. solid refrigerant such as solid carbon dioxide, a closed chamber for the refrigerant, a portion of said chamber including a solid metallic heat conductor in heat exchange relation to refrigerant therein and having an extended surface for heat absorption from the space or material to be cooled of greater area than the surface of the conductor presented in the refrigerant-containalong in the direction of the-refrigerant from the said surface presented for heat absorption being sufficient, by reason of its thickness with respect to the heat conductivity of the metal from which it is formed and the area of said extended surface exposed for heat absorption, to maintain said heat absorbing surface at an efl-ective refrigerating temperature lower than that of the space or material to be cooled, a wall cooperating with said extended heat-absorbing surface to form a duct through which air may flow from the space to be cooled into contact with said extended surface, a duct extended in the upper part of the space to be cooled and communicating with the duct formed adjacent to said heatabsorbing conductor surface, said extended-duct facilitating flow of warmer air over the heat absorbing surface from portionsof the space to be cooled remote from said surface, a gas escape pipe leading from the refrigerant chamber to the outside of the refrigerating apparatus, and means operable from without said chamber for controlling the escape of gas through said pipe.

13. In refrigerating apparatus for cooling bya solid refrigerant such as water-ice, brine-ice, or solid carbon dioxide, a solid' metallic heat conductor having a vertically positioned extended surface for heat absorption from the space or material to be cooled of greater area than the surface of the conductor presented in the refrigerant-containing chamber for heat transfer to the refrigerant, the capacity of said conductor to transmit heat along in the direction of the refrigerant from the said surface presented for heat absorption being suificient, by reason of its thickness with respect to the heat conductivity of the metal from which it is formed and the area of said extended surface exposed for heat absorption, to maintain said heat-absorbing surface at an effective refrigerating temperture lower than that of the space or material to be cooled, whereby said heat-absorbing surface is adapted to absorb a larger amount of the heat to be transmitted by said conductor, together with a horizontally-extending duct for facilitating the flow of warmer air over said verticallyextended surface from portions of the space to be cooled remote from said surface.

EDWARD RICE, JR. 

